Steve Rothstein is a frequent flier. Actually, frequent doesn't even begin to describe it. Since 1987, he has flown nearly 40 million miles, all on American Airlines' dime.

In 1987, American Airlines was struggling and desperate for money, so they started offering an unlimited lifetime airpass for $350,000, hoping for an infusion of cash. Just 66 people purchased the AAirpass before the program was discontinued, but for those lucky few who got on board early, it was quite the deal.

"I would put in little pins when I went to places. Here's Zurich. Frankfort. Munich. France. All places that I went to dozens and dozens of times," Rothstein told ABC News' John Berman. "London. Probably five or six hundred trips in my lifetime. My shampoo all came from London for the last 30 years."

AAirpass holders became American Airline VIPs, with virtually unlimited first class flight options for themselves and a companion.

Rothstein estimates he flew from his home in Chicago to New York a thousand times, Los Angeles and San Francisco 500 times, Paris and Sydney 80 times, all without paying a dime and racking up frequent flier miles. He says he thought nothing of flying strangers with him or picking up a friend in Los Angeles and heading to Paris for a quick visit to the Louvre.

That was all before American cracked down, canceling his airpass three years ago, after an investigation found the airline was losing millions of dollars to these extreme frequent fliers. The airline said Rothstein had abused the system by booking flights he never planned to use.

But Steve says he didn't do anything wrong, and he's suing the airline, hoping to get his pass back.

"A deal's a deal. I've made deals in business which I've regretted five minutes later. But a deal's a deal," Rothstein said.

Another AAirpass user, Jacques Vroom, who was also investigated and lost his pass, is also suing the airline.

In a statement to ABC News, American Airlines spokeswoman Mary Sanderson says cases like Rothstein's and Vroom's are an "extremely small percentage of our overall AAirpass accounts, but fraudulent activity costs all of our customers money."

The litigation over whether this was abuse of the system or a bad business plan is on hold for now, since American Airlines filed for Chapter 11 bankruptcy late last year.